Abstract: The present invention relates to a method for indicating an electric discharge in a non-conducting medium (22) between a rolling element (20) and a raceway (16, 18) in a bearing (12) of an electric drive system (10). The method comprises: remotely detecting radio frequency signals emitted from the electric drive system, which signals comprise a radio frequency signal associated with an electrical discharge in the non-conducting medium, processing the detected radio frequency signals to estimate the electric discharge, and indicating the estimated electric discharge. The present invention also relates to a corresponding device (30, 50, 70, 90) for indicating an electric discharge in a non-conducting medium between a rolling element and a raceway in a bearing of an electric drive system.

Abstract: A defect in a roof membrane is detected by applying a DC voltage between the roof deck and a perimeter conductor and using a detection probe pair to provide a signal indicative of the differences in voltage detected by the pair of probes so as to allow the operator to locate the defect by moving the probes to different locations. The probes are mounted on a rigid common frame such that the probe pair has a fixed separation and the frame includes a handle portion which allows ready manipulation of the frame carrying the probes by the operator. The receiver provides an audible signal emitter to the operator and includes a calibration circuit arranged to automatically maintain, despite changes in voltage applied between the roof deck and the peripheral conductor, a “0” set calibration point so as to indicate at the calibration point when zero difference in voltage is detected.

Abstract: A method for measuring the insulation resistance in an information technology (IT) network. The IT network has a DC voltage intermediate circuit and at least one self-commutated converter having at least one first and one second power switch. The IT network also includes a measuring arrangement for measuring the intermediate circuit voltage relative to ground potential comprising a voltage divider and two assigned potential measuring devices. The method has an offline and an online measurement, wherein, during the offline measurement, all of one of the first and second power switches are closed and the potentials Up and Um, respectively, and also the intermediate circuit voltage are measured and the insulation resistance Rf is determined therefrom. During the online measurement, the two potentials Up and Um are measured and the temporal profile of the measurements is compared with the offline measurement.

Abstract: A circuit and a method are provided to produce a noise-free multi-input I/O pad for an integrated circuit chip. The circuit includes a normal mode internal node, which connects to normal mode circuitry and a test mode internal node, which connects to test mode circuitry. There are separate transfer devices which connect the I/O pad to the normal mode circuitry and to the test mode circuitry. In addition, a third transfer device, a load device, and a new intermediate internal node are added to prevent negative input voltage swings which occur on the I/O pad during the normal mode from causing the transfer gate to the test mode circuitry from turning ON causing chip failure.

Abstract: There is provided a test method for detecting the presence or absence of a defect in a spark plug insulator, including a reference voltage determination process, a test area determination process, a test voltage determination process and a current detection process. In the reference voltage determination process, a reference voltage VF is determined. In the test area and voltage determined processes, test area and voltage are determined so as not to incur a flashover on the basis of a reference insulator of the same material, shape and size as the spark plug insulator when the reference insulator is placed in position between first and second test electrodes. In the current detection step, the test voltage is applied between the first and second test electrodes to detect an electric current between the first and second test electrodes.

Abstract: An automatic failed roll condom detection and removal apparatus wherein failed roll condoms are rapidly removed from a testing mandrel such that shut down of the testing and handling equipment is not required. Detection means detect the presence of a failed roll condom on a testing mandrel as it returns from the testing and removal station and ejection means remove the failed roll condom from the mandrel. The ejection means has a series of rotating brushes having relatively stiff bristles, the brushes being mounted on a reciprocating carriage in ascending manner in the mandrel return travel direction. When a failed roll condom is detected, the shuttle carriage return rate is slowed and the rotating brushes are brought into contact with the failed roll mandrel, each brush in succession pushing or rolling the condom higher on the mandrel until the final brush ejects the condom.

Abstract: A method of water absorption for a generator stator winding insulator using a cross capacitance involves detecting a state of the insulator of the stator winding of the generator using a theory of the cross capacitance, and carrying out the water absorption test of the insulator of the stator winding of the power generator using the detected state in the detecting.

Abstract: An insulation inspection apparatus includes a chamber in which a stator with a winding can be stored, an electrode movable along the outer circumference of a coil end of the stator winding, a voltage application unit applying voltage between the coil end and electrode, a sensor unit sensing leakage current and/or voltage drop between the coil end and electrode, and a pressure reduction unit reducing the pressure in the chamber.

Abstract: A motor insulation deterioration detection device wherein a capacitor provided in a power supply section is utilized as a power supply for motor insulation deterioration detection, with provisions made to be able to detect insulation resistance regardless of the value of the voltage developed across the capacitor. The motor insulation deterioration detection device includes: a first contact which connects one end of the capacitor to ground; a second contact which connects the other end of the capacitor to a motor coil via a detection resistor; a unit which, using the detection resistor, detects a current flowing through a closed circuit formed by the first contact, capacitor, second contact, detection resistor, motor coil, and ground; a unit which detects the voltage developed across the capacitor; and a unit which calculates the insulation resistance value based on the current detection value and the voltage detection value.

Abstract: A power control apparatus for a motor is disclosed. The power control apparatus includes: a moisture sensor for detecting moisture soaking into a housing including the motor; and a switching unit which is switched by an output signal of the moisture sensor, and switches on or off an AC power-supply signal applied to a driver circuit for providing the motor with a drive power-supply signal. Therefore, if moisture soaks into the suction apparatus including the motor, the AC power-supply signal applied to the driver circuit is blocked due to the moisture, such that a user can be protected from electric shock.

Abstract: A method for predicting long-term electrical insulation properties of composite materials in a moist environment. The method including the steps of providing a specimen, and testing the specimen to determine moisture content values and leakage current values at predetermined time intervals. The method further including the steps of determining a moisture-leakage current factor from the moisture content values and leakage current values, and using the moisture-leakage current factor to determine electrical insulation properties of the specimen.

Abstract: A method and apparatus for dry testing non-conductive containers for carrying people are disclosed. Two conductive materials placed on opposite sides of a material being tested. High voltage is applied to one of the conductive materials while a ground lead is attached to the other conductive material. Electric current is measured from the grounded conductive material to identify any breakdown of the dielectric properties of the material being tested.

Abstract: An automatic failed roll condom detection and removal apparatus wherein failed roll condoms are rapidly removed from a testing mandrel such that shut down of the testing and handling equipment is not required. Detection means detect the presence of a failed roll condom on a testing mandrel as it returns from the testing and removal station and ejection means remove the failed roll condom from the mandrel. The ejection means has a series of rotating brushes having relatively stiff bristles, the brushes being mounted on a reciprocating carriage in ascending manner in the mandrel return travel direction. When a failed roll condom is detected, the shuttle carriage return rate is slowed and the rotating brushes are brought into contact with the failed roll mandrel, each brush in succession pushing or rolling the condom higher on the mandrel until the final brush ejects the condom.

Abstract: A hot stick testing apparatus and method including a pair of generally ring-shaped electrodes spaced from one another at a predetermined distance. Each electrode has a central opening configured to receive the diameter of a hot stick under test positioned longitudinally through the central opening of both electrodes. Each electrode includes relatively smooth, outer surfaces presenting generally curved contours to enhance generating a relatively high electrical field intensity between the electrodes, without causing electrical flashover or arcing in the air gap between the electrodes. One of the electrodes is operatively connected to a source of high voltage and the other to ground. The testing apparatus has the ability to generate an electrical field intensity between the electrodes of about 140 to 170 kv per centimeter with an applied voltage in the range of 60 to 80 kv to the energized electrode.

Abstract: An algorithm is provided for a frequency domain reflectometer which takes into account both attenuation per unit length of transmission line and phase shift per unit length of transmission line in a modified Inverse Fourier Transform that converts a frequency domain complex reflection coefficient into a more accurate time domain reflection coefficient so that the distance to a fault can be readily determined.

Abstract: An insulation detecting device having a capacitor and a DC power source, insulated from a ground potential part. A voltage detecting unit, detects a voltage across the capacitor. A first switching unit connects the capacitor to the DC power source in series for a first preset time shorter than a time taken for completely charging the capacitor. A second switching unit connects the capacitor between a positive terminal of the DC power source and the ground potential part in series for a second preset time. A third switching unit connects the capacitor between a negative terminal of the DC power source and the ground potential part in series for the second preset time. A fourth switching unit connects the voltage detecting unit to the capacitor after the first to third switching units are turned off. A computing unit estimates a voltage across the power source.

Abstract: A system and method for testing polymer insulators is provided. One embodiment includes applying a voltage to a grading shield that is oriented about a top region of a polymer insulator and to a high voltage lead of the polymer insulator; detecting a leakage current across the polymer insulator; determining a resistive current component from the detected leakage current; comparing the resistive current component to a predefined criteria; determining that when the resistive current component is greater than the predefined criteria when the applied voltage is applied, the polymer insulator has failed the test; and determining that when the resistive current component is less than or equal to the predefined criteria when the applied voltage is applied, the polymer insulator has passed the test.

Abstract: A condom testing apparatus having a plurality of electrically conductive mandrels having condoms loaded thereon, a first set of condom-contacting electrode members, a second set of condom-contacting electrode members, and a gapped electrical circuit between each of the mandrels and the first set of condom-contacting electrode members and between each of the mandrels and the second set of condom-contacting electrode members during testing, wherein defects within a condom being tested are detected by passage of current between the mandrels and the first and second sets of condom-contacting electrode members, wherein the first set of condom-contacting electrode members contacts less than 100 percent of the circumference of each of the condoms and the second set of condom-contacting electrode members contacts less than 100 percent of the circumference of each of the condoms, such that two condoms can be tested at once.

Abstract: In a device for the investigation of components of a generator which border on a machine air gap (29) between stator and rotor (22), with the rotor (22) built in, by means of at least one moveable inspection probe (35), a simple, flexible and rapid mounting is ensured in that the device comprises a base unit (31) which can be secured to the rotor (22) on both sides, and which permits at least one inspection probe (35) to move in the machine air gap (29), both in an axial direction with respect to the generator axis and also in the circumferential direction of the machine air gap (29) over the whole circumference of the rotor.

Abstract: A method of testing a power module including a control gate, an emitter, a collector, at least one power component on a dielectric substrate and a diode connected in antiparallel with the power component measures partial discharges occurring between the emitter and the collector when an alternating current voltage source superimposed on a direct current voltage source is connected between the collector and the emitter of the power module. The voltage Vtest received by the power module between the collector and the emitter verifies at all times the condition Vtest>0 so that the diode never conducts. The power component is maintained in a turned off state during the test by a direct current voltage source connected between the control gate and the emitter.

Abstract: An object of the present invention is to provide a hot plate which is superior in thermal conductivity, is superior in temperature-rising/dropping property, particularly in temperature-dropping property, and has high cooling thermal efficiency at the time of cooling. The hot plate of the present invention is a hotplate comprising: a ceramic substrate; and a resistance heating element formed on the surface of said ceramic substrate or inside said ceramic substrate, wherein said ceramic substrate has a leakage quantity of 10−7 Pa·m3/sec (He) or less by measurement with a helium leakage detector.

Abstract: A process and an apparatus for measuring the impedance of a capacitive sample and thereby determining the leakage impedance and the loss angle. To suppress the effects of ambient power frequency fields coupling onto the test object, measuring frequencies on either side of the line frequency are imposed onto the test object. The voltage and current are captured using a detection system. These signals are digitised and processed using a computer to determine the real and imaginary voltages and currents at the two test frequencies. These components are then analysed to calculate the leakage impedance and phase angle at the two frequencies. By applying a linear interpolation between the two points, the impedance and loss angle at the line frequency can be measured.

Abstract: While a sealed package (3) prepared by wrapping conductive contents (1) with an electric-insulation film (2) is being conveyed by two conveyors (4, 4), front and rear, a conductor (5) disposed on one side of a conveyance path (A) and at least one of two conductors (6, 6), front and rear, disposed on the other side are simultaneously contacted with opposed surfaces of the sealed package (3) being conveyed. In this state, a high voltage from a high voltage source (7) is applied to the sealed package (3), and a current detector (8) is used to detect whether or not a change in current is occurring in the portion which is in contact with the conductor (5) and the portion which is in contact with at least one of the two conductors (6, 6) so as to find pinholes in the sealed package (3). Whether or not there is a pinhole in at least one of the opposed surfaces in the portion of the sealed package (3) where the contents (1) exist can be detected by simultaneous inspection from both surfaces.

Abstract: A new method is provided for evaluating the alignment of inner layers of interconnect layers. A test pattern is inserted within and as part of the process of creating a saw singulated plastic ball grid array substrate. The test pattern comprises a test point of reference for each inner layer of the substrate and multiple measurement points relating to the point of reference whereby each of these multiple measurement points is indicative of an amount of clearance or misalignment with respect to that inner-layer. By measuring electrical continuity or lack thereof between the point of reference and the respective multiple measurement points relating to the point of reference and by identifying which of the multiple points is shorted to the point of reference, the mis-alignment of the inner layers of the saw singulated plastic ball grid array substrate can be determined.

Abstract: A laminate comprising an insulation layer sandwiched between a pair of electrically conductive layers is prepared for electrical insulation testing by using a laser to remove a strip from at least one of the conductive layers proximate the edge of the laminate to electrically isolate a central, bulk portion of the conductive layer from the edges of the laminate. Conductive material that may be smeared across an edge of the laminate will not therefore provide an electrical short between the portion of the conductive layer surrounded by the slot and the second conductive layer on the opposite side of the insulation layer.

Abstract: A wire testing method and apparatus tests wire (30) in-situ in a rigidly installed state, such as an aircraft (100). Stray currents are compensated by an apparatus for rapidly switching the excitation voltage and ground. The apparatus outputs a stray current signal (721), a detected current signal (731), and a difference signal (830) indicative of a measurement with the stray current signal removed.

Abstract: A method of inspecting insulators such as spark plug insulators for defects, whereby a plurality of insulators are inspected concurrently by being disposed with a plurality of first electrodes engaged in respective apertures in the insulators, and with apertures formed in a second electrode being disposed to peripherally enclose respective insulators. With the insulators and electrodes set in a closed chamber under high air pressure, and high voltage applied between the first and second electrodes, any defect is detected based on a level of leakage current which then flows.

Abstract: A system for monitoring air pressure in a telecommunications network comprises a plurality of monitoring units, at least one device server, a computer network, and a terminal. Each monitoring unit is connected to a device server. A user at the terminal receives air pressure data from the monitoring units over the computer network.

Abstract: A leakage inspection method for a sealed container in which a liquid of a non-electrolyte is contained for judging whether a defect exists in the container, the method comprising the steps of applying an inspection AC voltage through electrodes from an inspection power source unit; detecting an AC current flowing through the container and the contained liquid by means of a current detector; obtaining a digital value corresponding to an absolute value of the instantaneous value of the detected AC current; successively totaling the digital values during a totaling period having a specific relation to the waveform of the AC current whereby the total value of the digital values corresponding to the absolute values of the respective instantaneous values of the AC current is arithmetically operated and judging that the defect exists in the container when the total value as the value to be judged is larger than a setting value.

Abstract: Arrangement to test HF tightness of a junction between two adjacent parts including HF generator (4), HF line that guides the signal over junction (1), measuring device (10) as well as a signal analyzer. HF line includes two waveguides (5a, 5b) that have inner conductors (6a, 6b) connected all the way through by a connection conductor (9) and outer conductors (7a, 7b) interrupted and each connected with electrodes (8a, 8b). A capacitive coupling of the HF signal occurs on one side of the junction and a capacitive decoupling of the HF signal takes place on the other side. By comparing the measured transmission and/or reflection of the HF signal with a transmission or reflection characteristic for the junction, it can be determined if the junction is HF tight. This makes it possible to test HF shielded cases for HF tightness in a non-destructive manner and without interfering with the contents.

Abstract: A method for performing time domain reflectometry contemporaneously with recurrent transmissions, such as idle transmissions, on a computer network, such as a 100 BASE T protocol network is disclosed. This method comprises detecting the recurrent transmissions and then storing representations of those transmissions. A probe signal, such as a TDR signal, is then generated onto the computer network during the recurrent transmissions. A response of the network to the probe signal combined with the recurrent transmissions is then detected. The signal transmission characteristics of the network are then analyzable based on the response to the probe signal using the stored representations of the recurrent transmissions, using deconvolution, for example.

Abstract: A technique for detecting whether or not a pinhole is present in an organic film on a concrete surface, by detecting the conductivity of the concrete in advance. In the bottom portion of a measuring means body having a high-frequency oscillator accommodated therein, there are disposed electrodes which are insulated from each other through an insulating plate. Two electrodes are provided in parallel and are placed in contact with the surface of the lining film coating the surface of the concrete body. Thus, the electrodes are held in contact with the surface of the lining film, and a high-frequency signal is fed from the high-frequency oscillator to between the electrodes.

Abstract: The invention provides an efficient inspection method for inspecting a hermetically sealed package for pinholes, in which when a hermetically sealed package whose contents such as electrically conductive fluid or food are covered with an electrically insulating film is inspected for pinholes by using a high voltage, the inspection can be achieved with an extremely simple procedure while fully preventing occurrence of misoperations due to the atmosphere such as humidity during the inspection. In a hermetically sealed package in which contents 1 such as electrically conductive fluid are covered with an electrically insulating film 2, an electrical conductor 4 derived from a voltage output terminal of a DC high voltage power supply 6 is put into contact with or proximity to a side face portion 31 of the hermetically sealed package, by which the contents 1 in the hermetically sealed package 3 are electrified.

Abstract: A preferred method for identifying a type of abnormality in an insulation system of a power transformer comprises measuring dielectric losses in a section of the insulation system, calculating theoretical dielectric losses for the section based on the material properties, geometry, and temperature of the section, and generating a graphical representation of a percent difference between the measured and calculated dielectric losses. The preferred method also comprises comparing a shape of the graphical representation with a shape of one or more graphical representations of a percent difference between measured and theoretical dielectric losses in one or more other sections of insulation each known to have a specific type of abnormality.

Abstract: A method and system for determining the resistance of a winding insulation. The method includes applying a pulsed voltage having a maximum value and a minimum value to the winding insulation. The maximum and minimum values of the pulsed voltage are both negative values in certain exemplary implementations. The values of the maximum and minimum current flowing through the winding insulation are determined, and the winding insulation resistance is calculated based on the difference between the maximum and minimum current. A ground fault may be detected based on the calculated winding insulation resistance. The winding insulation monitoring system includes a sense resistor connected to the winding insulation and a pulsed voltage source is coupled to the sense resistor to apply the pulsed voltage to the winding insulation via the sense resistor.

Abstract: A nipple testing apparatus for testing the nipple end of condoms mounted onto a mandrel, the apparatus having an electrically conducted nipple-shaped cavity connected in electrical circuit to the mandrel, such that electrical current passing through the condom disposed between the mandrel and the nipple cavity indicates a defect in the condom.

Abstract: The invention is relative to a leaktight chamber (3) in which a liquid having electrical characteristics, preferably a conductive liquid, is introduced into a leaktight volume (33) between the cover (5) and the tank (4), and in that a value of electric quantities is measured which varies with the reduction of the liquid contained in the volume (33). In such a way the leaktightness is continually checked.

Abstract: An inspection method for inspecting a hermetricaly sealed package for pinholes in which electrically conductive contents are covered with an electrically insulating film, an electrical conductor connected to a high voltage output terminal of a DC high voltage power supply is put into contact with a side face of the hermetrically sealed package to electrify the contents. Next, a terminal of a lead wire which is grounded is put into close contact or proximity to an inspection portion of the package where pinholes are more likely to occur. Then, a discharge current derived fom the inspection objection portion that flows only when a pinhole is present is detected by discharge current detector.

Abstract: The printed circuit board testing apparatus for use to test the short circuit in an induction element is provided. The apparatus includes: a signal generating device for providing a first signal; an inducing device for performing a mutual inductance effect with the induction element and making the first signal to produce a second signal in response to the mutual inductance effect; a signal converting device for converting the second signal into a direct current signal and obtaining a peak value voltage from the direct current signal; a signal processing device for outputting a controlling signal according to the relationship between the peak value voltage and a reference voltage; and a warning device for generating a warning signal in response to the status change of the controlling signal when a relative voltage standard is not identical to a predetermined voltage standard, thereby judging whether there is any short circuit formed.

Abstract: A system for detecting defects in a layer of dielectric material is disclosed. The disclosed system comprises a first electrode, on which the layer is placed, at least one second electrode oppositely spaced apart from the first electrode and oppositely spaced apart from, but not in contact with, the top surface of the layer. A voltage, that is at least equal to the breakdown voltage corresponding to the spacing between the first and second electrodes in the absence of the material layer, is applied across the first and second electrodes. The presence and characteristics, such as the location and the cross sectional area, of defects are detected as a function of the flow of electrical from the first electrode to the at least one second electrode.

Abstract: Device to detect leaks and fatigue in membranes wherein the membrane consists of at least two membrane layers, and wherein at least one of the membrane layers includes a conductor on its inner surface that causes an alteration to a measured value in case of an alteration to either the membrane or the conductor.

Abstract: A sorting method of monolithic ceramic capacitors in which high reliable sorting can be efficiently achieved based on measuring an insulating resistance involves first performing a burn-in process, which applies not less than double of the rated voltage at the maximum working temperature to a monolithic ceramic capacitor. Thereafter, a high temperature insulation resistance measuring process, which involves measuring an insulation resistance while applying not less than the rated voltage at a temperature of not less than 70° C. to the monolithic ceramic capacitor, is performed so that monolithic ceramic capacitors having abnormal insulation resistances are eliminated. Preferably, the direction of applied voltage in the burn-in process agrees with the direction of applied voltage in the high temperature insulation resistance measuring process.

Abstract: In the temperature of 70-140 degrees C., the burn-in process of applying a voltage to monolithic ceramic capacitors so that the strength of the electric field applied between the internal electrodes opposing each other may be 7 30 kV/mm is performed. Subsequently, the insulation resistance of the monolithic ceramic capacitor is measured. The monolithic ceramic capacitors are sorted based on the insulation resistance measured during this insulation-resistance measurement process. In this case, it is sufficient to apply the burn-in process for 2-300 seconds.

Abstract: A cathode-anode apparatus is constructed whereby the wafer under test, connected to a conducting wire, forms the cathode terminal and a copper plate, also connected to a conducting wire, forms the anode terminal. The wafer under test and the copper plate are immersed in a CuSO4—H2O solution. A positive dc voltage is applied to the copper plate; the dc current ionizes the CuSO4 solution and forms Cu2+ ions. These Cu2+ ions will diffuse to the wafer surface. Most of the Cu2+ ions will accumulate in and around defective contacts or vias in the semiconductor surface making these defective contacts or vias readily identifiable.

Abstract: An apparatus for monitoring the status of the insulation on the wire in a winding in a device comprises a surrogate sample of insulating material having a thickness and properties selected to fail before the failure of the insulation on the wires in the winding, and a detector for detecting and indicating failure of the sample of insulating material. A method of monitoring the status of the insulation on the winding in a dynamoelectric device includes associating a surrogate sample of insulating material with the winding, monitoring the surrogate sample, and providing an alarm when the surrogate sample fails, which is predictive of the failure of the insulation on the winding wire.

Abstract: The integrity and quality of the internal or inside coating of a container, such as a can, is measured by attaching an electric terminal to the can, inserting an electrode into the can, applying an electric signal to either the electric terminal or the electrode, and measuring the current flowing between the terminal and the electrode as an electrolyte is being added to the can. By measuring the electric signal as the level of electrolyte is being varied, an indication can be achieved of the quality and integrity of the coating at various parts of the can.

Abstract: Methods are provided for detecting and locating leaks in liners used as barriers in the construction of landfills, surface impoundments, water reservoirs, tanks, and the like. Electrodes are placed in the ground around the periphery of the facility, in the leak detection zone located between two liners if present, and/or within the containment facility. Electrical resistivity data is collected using these electrodes. This data is used to map the electrical resistivity distribution beneath the containment liner or between two liners in a double-lined facility. In an alternative embodiment, an electrode placed within the lined facility is driven to an electrical potential with respect to another electrode placed at a distance from the lined facility (mise-a-la-masse). Voltage differences are then measured between various combinations of additional electrodes placed in the soil on the periphery of the facility, the leak detection zone, or within the facility.

Abstract: Apparatus and method to identify chafing of a conduit, thereby reducing the failure of any system which would be damaged or whose function would be impaired by abrasion of the conduit. Such a system may carry electrical power, fuel, other fluid, hydraulics, pneumatics, optical, or electromagnetic signals. Wear caused by rubbing against external structures is detected by wrapping the conduit with a sensing element, which may be a conductive wire, waveguide, fiber optic cable, or a tube (wound around the conduit or enclosing it) that holds a fluid under pressure. The sensing element is positioned so that chafing on the conduit electrically contacts, breaks, or punctures the sensing element well before the conduit fails.

Abstract: Apparatus for remotely determining the amount of current I flowing in a long, linear conductor, comprising a first sensor for measuring at a first location a magnetic field H arising due to current flow, a second sensor for measuring at a second location the same magnetic field H, a mounting mechanism for fixing the position of the first and second sensors in an unchanging, spaced-apart mutual configuration, calculating apparatus for calculating the vertical gradient H′ of the magnetic field on the basis of measurements made by the sensors, and further calculating apparatus for determining the current I on the basis of the equation I=H2/H′ where k is a constant.

Abstract: The invention includes apparatus and method for detecting defects in various barrier materials including surgical gloves and food packaging. Voltage is applied across electrodes and a barrier material and the voltage measured and compared with voltage control measurements for the same barrier material without a defect. Sensitivity of measurements is increased by adjusting partial pressure across the barrier material which is subjected to the passage of an ionized gas detected by suitable instrumentation.